Robust data routing in wireless networks with directional transmissions

ABSTRACT

A method and apparatus for routing the same data through independent routes between stations in a mesh network to increase the robustness of communications. The disclosed feature allows transmission of the same data stream via multiple routes from a source station (STA) to a destination station (STA). An extended routing request (RREQ) and routing reply (RREP) are utilized which provide a primary and secondary flag indication, which is utilized in combination with advanced programming for setting path cost metrics to assure independence of primary and secondary routes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and is a continuation of, U.S.patent application Ser. No. 15/387,457 filed on Dec. 21, 2016,incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF COMPUTER PROGRAM APPENDIX

Not Applicable

NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION

A portion of the material in this patent document may be subject tocopyright protection under the copyright laws of the United States andof other countries. The owner of the copyright rights has no objectionto the facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the United States Patent andTrademark Office publicly available file or records, but otherwisereserves all copyright rights whatsoever. The copyright owner does nothereby waive any of its rights to have this patent document maintainedin secrecy, including without limitation its rights pursuant to 37C.F.R. § 1.14.

BACKGROUND 1. Technical Field

The technology of this disclosure pertains generally to data routing indirectional wireless networks, and more particularly to recovering fromlink blockages in a directional wireless network.

2. Background Discussion

Link dynamics in millimeter-wave (mmWave) networks have characteristicswhich can be compared in some respects to transmission time. That is tosay, that blockage can arise frequently, in particular with indoorsetups or outdoor environments in response to object and/or stationmobility. In mmWave frequencies blockage can cause the received signalpower of a link to drop significantly, which renders the communicationlink inoperative. The cost of recovering from a blocked link inmulti-hop networks is significant in terms of both the time and datacommunications required to reestablish a connection.

Accordingly, methods are needed for recovering from blockages, or otherlink outages in a mesh network. The technology of this disclosureprovides this functionality while overcoming the shortcomings ofprevious routing protocols.

BRIEF SUMMARY

Path diversity may be needed to overcome blockage for delay sensitivedata content in mmWave mesh networks. However, typical wireless routingprotocols discover one best route from the source station (STA) and thedestination STA. These protocols are not configured to create asecondary path to cope with blockage. Hence, STAs do not transmitmultiple streams to make the end-to-end transmission robust.

Routing protocols specify how different network STAs communicate witheach other, disseminating information that enables them to select routesbetween any two STAs on a network. A method and apparatus are disclosedfor creating a secondary path in addition to the primary path in orderto route the same data contents through both paths to overcome linkfailure problems in wireless communication networks.

Generally speaking, the disclosure teaches a new routing protocol inwireless networks in which primary and secondary path discovery isperformed. The protocol utilizes antenna patterns and the beamforming(BF) training information to select the next-hop of the secondary paththat is spatially uncorrelated with the primary path next-hop. A newhandshaking mechanism is performed to coordinate the reception of datafrom the two routes at the destination station to minimize errors anddelays in reception.

The specification describes the target as being mesh networkingapplications which can be applied to wireless LAN (WLAN), wirelesspersonal area networks (WPAN), and outdoor wireless communications.Thus, the target applications can range from Wi-Fi like networks,internet of things (IoT) applications, backhauling of data by meshnetworking, next generation cellular networks with D2D communications,IEEE802.11s, IEEE802.11ad, and IEEE 802.15.4 (ZigBee), Device-to-device(D2D) communications, Peer-to-peer (P2P) communications, and the like.

A number of terms are found in the disclosure whose meanings aregenerally utilized as described below.

AODV: Ad-hoc On-Demand Distance Vector, a routing protocol for datapackets in ad-hoc wireless networks.

D2D: Device-to-Device communications.

DMG: Directional Multi-gigabit.

Mesh networks: In a mesh network topology each node relays data for thenetwork, and all mesh nodes cooperate in the distribution of data in thenetwork. Mesh networks are a type of ad-hoc (spontaneous, impromptu, oron-the-fly construction) network.

MIMO: Multiple Input Multiple Output; communications between two deviceswith multiple streams of data.

MU-MIMO: Multi-User Multiple Input Multiple Output; communicationsbetween a device and two or more nodes with single or multiple streamsof data per node.

Multicast: In networking, multicasting is a one-to-many form of groupcommunication implemented at layers above the physical layer whereinformation is addressed to a group of destination STAs simultaneously.

P2P: Peer-to-peer (P2P) communications arise when two or more stationsare connected and share resources without going through a separatecontroller/server. A P2P network can be an ad hoc connection.

RREQ: Routing Request, a packet used in data routing protocols todiscover the path between the source STA and the destination STA.

RREP: Routing Reply, a packet transmitted in response to RREQ in routingprotocols. Upon reception of RREP by a source STA it can starttransmitting the data packets.

RSS: Received Signal Strength (RSS) is a measurement of the powerpresent in a received radio signal.

SISO: Single Input Single Output; communications between two deviceswith a single stream of data.

STA: Station; a logical entity that is a singly addressable instance ofa medium access control (MAC) and physical layer (PHY) interface to thewireless medium (WM).

Unicast: In networking, unicast is a one-to-one connection between twoSTAs.

Further aspects of the technology described herein will be brought outin the following portions of the specification, wherein the detaileddescription is for the purpose of fully disclosing preferred embodimentsof the technology without placing limitations thereon.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The technology described herein will be more fully understood byreference to the following drawings which are for illustrative purposesonly:

FIG. 1 is a data field diagram of a conventional clear to send (CTS)frame.

FIG. 2 is a topology diagram of a conventional wireless network havingmultiple peer nodes, shown subject to data loss in response to ablockage.

FIG. 3 is a topology diagram of an example wireless network havingmultiple peer nodes through which primary and secondary routing pathsare determined according to an embodiment of the technology of thisdisclosure, to overcome the effects of a blockage on either of theroutes.

FIG. 4 is a bar chart comparing received signal strength in response toblockage, and the use of two paths for sending the same data accordingto an embodiment of the technology of this disclosure.

FIG. 5A and FIG. 5B are a flow diagram-timeline of wireless data routingof the same data through a primary and secondary route according to anembodiment of the technology of this disclosure.

FIG. 6 is a data field diagram of an extended routing request (RREQ)utilized according to an embodiment of the technology of thisdisclosure.

FIG. 7 is a data field diagram of an extended routing reply (RREP)utilized according to an embodiment of the technology of thisdisclosure.

FIG. 8 is a data field diagram of an extended routing clear-to-send(CTS) frame utilized according to an embodiment of the technology ofthis disclosure.

FIG. 9 is a topology diagram of an example wireless network, showingspatial correlation impacts of routing which are overcome according toan embodiment of the technology of this disclosure.

FIG. 10 is a packet transmission diagram of BF sector level sweep (SLS)utilized according to an embodiment of the technology of thisdisclosure.

FIG. 11A and FIG. 11B are data field diagrams of an SSW feedback frameutilized according to an embodiment of the technology of thisdisclosure.

FIG. 12 is a beam pattern diagram showing use of best sector informationobtained through SLS BF training as a metric for correlation ofsecondary routes according to an embodiment of the technology of thisdisclosure.

FIG. 13 is a flow diagram of a routing protocol performed in a sourcestation routing to secure both primary and secondary routes for the samedata according to an embodiment of the technology of this disclosure.

FIG. 14 is a flow diagram of processing an RREQ at intermediate nodeswith primary and secondary path discovery according to an embodiment ofthe technology of this disclosure.

FIG. 15 is a flow diagram of selecting secondary links from neighborstations which are uncorrelated with the primary path as performedaccording to an embodiment of the technology of this disclosure.

FIG. 16 is a geometric depiction of secondary route selection utilizedaccording to an embodiment of the technology of this disclosure.

FIG. 17A through FIG. 17E are topology diagrams showing stages ofrouting the same data along primary and secondary paths according to anembodiment of the technology of this disclosure.

FIG. 18 is a data transmission diagram showing data transmission by lasthop relays on the primary and secondary paths according to an embodimentof the technology of this disclosure.

FIG. 19 is a data transmission diagram showing use of RTS/CTS on theprimary and secondary paths according to an embodiment of the technologyof this disclosure.

FIG. 20 is a message flow diagram showing handshaking for coordinatingbetween primary relay, secondary relay and destination according to anembodiment of the technology of this disclosure.

FIG. 21A and FIG. 21B are a flow diagram of simultaneous data packetreception at the destination STA from the primary and secondary relaysaccording to an embodiment of the technology of this disclosure.

FIG. 22A and FIG. 22B are data transmission diagrams of transmissions bythe primary relay, destination STA, and secondary path relays accordingto an embodiment of the technology of this disclosure.

FIG. 23 is a message flow diagram of data transmission by the secondarypath relay when the transmission by the primary path relays fails, asutilized according to an embodiment of the technology of thisdisclosure.

FIG. 24A and FIG. 24B are a flow diagram of conditional data packetreception at the destination STA from the secondary STA according to anembodiment of the technology of this disclosure.

FIG. 25 is a block diagram of a single-input-single-output (SISO)station (STA) according to an embodiment of the technology of thisdisclosure.

FIG. 26 is a block diagram of a single-input-single-output (MIMO)station (STA) according to an embodiment of the technology of thisdisclosure.

DETAILED DESCRIPTION

1. Introduction.

An apparatus and method for robust data routing to overcome the effectsof blockage, by utilizing a secondary path transmission to improverobustness and reception quality. Elements of the routing protocolinclude selection of spatially uncorrelated primary and secondary pathlinks. Protocol operation comprises selection of links for neighbor STAsuncorrelated with the primary path. For example applying the routingprotocol on a mmWave mesh network, and having data reception from tworoutes at the destination STA as any of the following situations: (1)uncoordinated reception; (2) coordinated reception: combining receivedsignal powers; or (3) coordinated reception: conditional reception fromsecondary route.

1.1. Benefits Provided.

Robust data routing in mmWave mesh networks are described which areconfigured to utilize a secondary path to allow the same data packets tobe transmitted through both the primary and secondary paths. Thedisclosure describes a set of routing protocol rules to discover theprimary and secondary paths.

The disclosure also teaches a method to discover a secondary path thatis not spatially correlated with the primary path so that diversity isachieved against blockage effects. The protocol takes advantage of thecharacteristics of communications at the mmWave networks enablingspatial re-use between primary path and secondary path communications.The disclosure additionally proposes a coordination method for datareception at the destination station from the two routes.

2. AODV Routing Summary.

Ad-hoc on-demand distance vector (AODV) is a routing protocol toestablish an end-to-end communication route through multiple hoprelaying. With AODV, the route from source STA to destination STA willbe determined by the following procedure: (1) Source STA transmits RREQframes in multicast fashion; (2) Intermediate STAs propagate the RREQframes in multicast fashion; (3) Destination STA replies back with RREPframe toward the source STA in unicast fashion (remembering the chain ofnext-hop STAs); (4) Intermediate STAs propagate the RREP toward thesource STA in unicast fashion (remembering the chain of next-hop STAs);(5) Upon reception of the RREP frame, the source STA remembers thenext-hop STA, and starts data communication using the route procedure byRREQ/RREP handshaking.

AODV and typical routing protocols discover one best route from thesource STA to the destination STA. They do not create a secondary pathto cope with blockage. Hence, STAs do not transmit multiple streams tomake the end-to-end transmission robust.

3. Existing RTS/CTS Procedures.

FIG. 1 shows an example of a state-of-the-art CTS frame as described in802.11ad specifications, showing the fields, with a field number abovethe figure and the number of octets per field shown below the framediagram. It will be appreciated that ready-to-send (RTS), clear-to-send(CTS) are data communication procedures. The CTS frame is shown withthese fields: (1) frame control, (2) duration, (3) receiver address(RA), (4) transmitter address (TA), (5) frame check sequence (FCS). In802.11 WLAN systems, the RTS/CTS procedure is used to protect datatransmission on a particular link.

For all directional Multi-gigabit (DMG) CTS frames sent in response toRTS frames, the duration value is the value obtained from the durationfield of the immediately previous RTS frame, minus the time (inmicroseconds) required to transmit the DMG CTS frame and itsshort-interframe-space (SIFS) interval. Otherwise, the duration field isset to the remaining duration of the transmission slot time.

The RA field of the frame is copied from the TA field of the immediatelyprevious RTS frame to which the DMG CTS is a response. The TA field isthe MAC address of the STA transmitting the DMG CTS frame.

4. Robust Routing Embodiments.

A mmWave mesh network is described by way of example and not limitation,as it will be appreciated that the described protocol is applicable to anumber of node-to-node wireless communications situations which mightnot be considered a mmWave mesh network.

FIG. 2 is a topology diagram showing an example routing path 10 fromsource STA to destination STA, illustrating a case in which the selectedpath has been blocked during data transmission resulting in linkfailure. In the figure, STAs A, B, C, D, and E are shown by way ofexample in a local wireless mesh. A routing path 12 from source STA Athrough intermediate STA C to destination STA E is shown being blocked14.

Due to movement of the STAs or the surroundings, link blockage canarise. In the figure a source STA, “A” has packets intended todestination STA “E”. Using an on-demand routing protocol, the pathselected from source STA to destination STA is shown 12. After datatransmission commenced this path became blocked 14. If the blockagepersists for a sufficient period of time, retransmissions and feedbackmessaging would both fail. Detecting this blockage and employingtechniques to recover from it in mmWave networks, such as performing aself-healing routing procedure, involve the consumption of significantmessaging overhead and time.

4.1. Overview of Robust Routing.

FIG. 3 illustrates an example routing topology 10′, depicting the samesituation as in FIG. 2, but in this case the disclosed protocol isconfigured to route the same data through both a primary path (solidline) 12 and secondary path (dashed) 16, from a source STA (STA A inthis example) to a destination STA (STA E in this example) thatprocesses the signals from the two paths. Despite a blocking object 14arising on the primary path, a communication outage does not occurbecause of the transmission of the secondary path.

It should be appreciated that routing the primary and secondary dataalong the same path from STA A through STA C to STA E, would notovercome the blockage situation. However, with the introductions of aform of path diversity 16, as seen in the figure, robustness of datarouting in mmWave can be achieved. As depicted in the figure, thesecondary path 16 allows communications to be achieved withoutdisruption from the source STA to the destination STA. The source STAcan utilize both paths to transmit the same data to the destinationsimultaneously.

4.2. Effect of Blockage and Secondary Path on Reception Quality.

In mmWave communications, link blockage can cause significant signallosses (e.g., most often in the range of approximately 18-30 dB loss) ofthe received signal power at the receiving STA. In view of the alreadytight link budget that exists in mmWave frequencies due high free spacepath loss (FSPL) and large O₂/H₂O absorption, this blockage loss couldrender a link inoperative.

FIG. 4 shows some representative comparison between the received signalstrength (RSS) (assuming dBm scale) for a few cases: (a) from theprimary path if unblocked, (b) from the primary path if it is blocked,(c) from both paths if unblocked, (d) from both paths with one of themblocked. In this example the primary unobstructed path, for example is a−60 dBm primary path with obstruction (blockage), comprising a loss of20 dB, which results in a −80 dBm RSS.

RSS at the destination STA, if both primary and secondary paths areunobstructed, is −57 dBm in this example for bar (c) in the figure. On adB scale, 3 dB increase in signal is achieved when combining the powerfrom both paths at the receiver, assuming equal RSS from each path.

Bar (d) in the figure shows RSS at the destination STA if only one pathis obstructed. The obstructed path contributes a minor addition to theRSS on a dB scale, such that if the unobstructed path RSS is −60 dBm andthe obstructed path is −80 dBm, the resultant RSS is −59.96. Comparingcases (b) and (d) from the figure shows the immense importance of havingpath diversity against blockage.

4.3. Elements of the Routing Protocol.

FIG. 5A through FIG. 5B illustrates an example embodiment 30 of amessaging flow-timeline of securing a primary and secondary path fromsource 32, through intermediate STAs 34, to a destination 36, withrespect to a timeline 38. The disclosed protocol sets the primary pathand secondary path from a source STA to a destination STA, in responseto using modified RREQ and RREP information elements that are termedextended RREQ and extended RREP, respectively.

Following the flow of FIG. 5A, the protocol is triggered by source STA32, which is seeking to send a spatial stream 40 in a robusttransmission through intermediate STAs to a destination STA. The routingprotocol starts by broadcasting an extended RREQ 42 to intermediatenodes (STAs) with its route flag set to primary. The rules for theprimary route at the source STA, destination STA and the intermediateSTAs (possible relays) follow those of the baseline routing protocol,which by way of example and not limitation is AODV, except for pathmetric cost adjustment due to MIMO capability.

At block 44 an intermediate node, which is MIMO capable, weighs its pathcost favorably, and propagates in a unicast manner the primary RREQ 46,to another intermediate STA or to destination STA 36. The destinationstation selects a primary path 48 and transmits an RREP back toward thesource, which is picked up by intermediate STA 34 which propagates 50the RREP to source STA 32, which secures 52 the primary route.

When the primary route is secured source STA triggers 52 path discoveryof a secondary route by transmitting 52 an extended RREQ with its routeflag set to secondary. Then as seen in FIG. 5B, the intermediate STAruns a modified AODV 54 and performs cost adjustments for MIMOcapability and for secondary independence, then propagates 56 using aunicast technique this secondary RREQ to another intermediate STA or todestination STA 36 which evaluates 58 the secondary route path cost,selects a secondary path and transmits RREP to the intermediate 34.Intermediate 34 then propagates 60 this secondary RREP to source STA 32,which secures 62 the secondary route, and transmits 64 the same contentthrough both the primary and secondary routes.

According to the disclosed protocol, the intermediate STAs and thedestination STA deal differently with the secondary RREQ. They employcertain rules in the disclosed protocol which encourage the following.(a) The inclusion of MIMO STAs on the primary and secondary route to beable to use advanced physical layer MIMO communications schemes, such asspatial multiplexing and MU-MIMO. (b) Discovering of an end-to-end routethat is not overlapped with the primary route.

FIG. 6 and FIG. 7 illustrate example embodiments of an extended routingrequest (RREQ) information entity (IE) and an extended routing response(RREP) IE, respectively.

In FIG. 6 the RREQ fields are depicted as follows.

-   -   1: IE ID—a sequence identifier of RREQ for this source;    -   2: length—length of the RREQ IE;    -   3: SA—source address;    -   4: SSEQ—source sequence number associated to the route;    -   5: Broadcast ID—incremented for each RREQ by source;    -   6: DA—destination address;    -   7: DSEQ—destination sequence number associated to route;    -   8: Route Flag—flag indicating primary or secondary route; and    -   9: Metric—path cost metrics.

In FIG. 7, fields of the routing reply (RREP) IE are as follows.

-   -   1: IE ID—a sequence identifier of RREP for this destination;    -   2: length—length of the RREQ IE;    -   3: SA—source address;    -   4: DA—destination address;    -   5: DSEQ—destination sequence number associated to route;    -   6: Route Flag—flag indicating primary or secondary route;    -   7: Lifetime—time which route is valid; and    -   8: Metric—path cost metrics.

In both of these elements a new message; the route flag, is added. Theroute flag is one bit of information that indicates a primary or asecondary route for either the extended RREQ or RREP IE. Also, as withany information element, a distinct IE ID is used for this extended RREQand extended RREP. This allows any STA receiving these packets torecognize them from the (regular) RREQ and RREP packets of thestate-of-the-art AODV protocol.

4.3.1 Routing CTS.

The routing CTS frame is a modified CTS frame that is used to coordinatethe transmissions of the relays on the primary and secondary paths. Italso serves as a grant frame to STAs that did not solicit it with a RTSframe.

FIG. 8 illustrates field contents of an extended routing CTS frame,having the following fields. Comparing this with FIG. 1, it is readilyseen that this frame additionally includes the fields: SA, DA, lifetime,and time offset. It should be noted that in general four types ofaddress fields are used in sending a frame over multiple hops, forinstance SA, DA, TA, and RA. SA (Source Address) is an additional fieldthat indicates who the frame is originated from. SA is unchangedthroughout multiple hops when the frame travels over multiple hops. DA(Destination Address) is an additional field that indicates who theframe is destined to. DA is unchanged throughout multiple hops when theframe travels over multiple hops. TA (Transmitter Address) indicates whotransmitted the frame physically. TA differs hop by hop when the frametravels over multiple hops. RA (Receiver Address) indicates who issupposed to receive the frame physically. RA differs hop-by-hop when theframe travels over multiple hops.

1: Frame control: contains information about the type of the frame,power management information, and so forth;

2: Duration: Duration field of the immediately previous RTS frame, minusthe time, in microseconds, required to transmit the DMG CTS frame andits SIFS interval;

3: RA: MAC address of intended STA to receive this CTS frame;

4: TA: MAC address of the STA transmitting the DMG CTS frame;

5: SA: Source (originator) STA MAC address;

6: DA: Destination (final) STA address;

7: Lifetime: The time for which the STA receiving the CTS consider thedata it has in its buffer to be valid;

8: Time Offset: A time offset relative to a reference timesynchronization upon which transmission of data by the CTS recipient STAoccurs;

9: FCS: A frame check sequence that validates the reception of the framecontents.

4.4. Selection of Spatially Uncorrelated Path Links.

In this section, a method for selection of a secondary routing path thathas its links spatially uncorrelated with the links of the primary pathis described. One way of estimating spatial correlation in beamformed(BF) communications is to obtain the difference between the BF sectorsin the angular domain.

FIG. 9 illustrates an example topology 70 showing a primary route 72,and two possible secondary routes 76 and 78. It should be appreciatedthat secondary route (dotted) 78 is spatially correlated with primaryroute (solid) 72, as it follows a similar path, such that it may getblocked by the same blocking object 74 as was the primary path 72. Aspatially independent route (dashed) 76, however, is subject to a lowerprobability in getting blocked by the same objects blocking the primaryroute. Thus, in the figure, the case is depicted in which a secondarypath is selected without considering spatial correlation with theprimary path. The blocking object may in this case block both theprimary path and the secondary path. While another spatially independentroute has a lower probability of getting blocked by the same objectsblocking the primary route. A similar problem can arise when thetransmitter STA or receiver STA are moving. If the secondary route isspatially correlated with primary route, both of the routes may beblocked as a result of the mobility of the STA. The information ofcorrelation of BF patterns are obtained from the BF training data.

FIG. 10 illustrates an example of BF sector level sweep (SLS) trainingas implemented in 802.11ad. In the figure, an example 90 is seen of BFSector Level Sweep (SLS) 92 training as implemented in 802.11ad, showingtransmit sector sweep 94 from STA 1 as an initiator sector sweep 96,followed by a responder sector sweep 98 in which STA 2 performs atransmit sector sweep 100, to which STA 1 generates sector sweepfeedback 102, to which STA 2 generates a sector sweep ACK 104. The bestSector ID, Antenna ID, SNR and Beamformed link primary tenancy timeinformation are fed back with the Sector Sweep (SSW) Feedback. STAs willlearn directional transmission related information through the BFtraining process. The best sector ID information towards another STA isrecorded and used in the spatial correlation computation.

FIG. 11A and FIG. 11B illustrate conventional data structures forcontrolling SSW feedback. In FIG. 11A is seen an SSW feedback framedepicted with the following fields.

-   -   1: Frame Control—type of frame, power management. etc.    -   2: Duration    -   3: RA—Receive Address    -   4: TA—Transmit Address    -   5: SSW Feedback    -   6: BRP Request    -   7: Beamformed Link Maintenance    -   8: FCS

In FIG. 11B are shown the subfields in the SSW feedback field.

-   -   1: Sector Select    -   2: DMG Antenna Select    -   3: SNR Report    -   4: Poll Required    -   5: Reserved

FIG. 12 illustrates beam pattern lobes 110 of a STA in mmWavecommunications. Best sector information obtained through SLS BF trainingis utilized as a metric for correlation of secondary routes with theprimary route. In the figure the best sector towards the next-hop STA inthe primary path is shown, with: (1) section 112 having limited angularseparation from another best sector, which is section (2) 114, of around22 degrees on the horizontal plane; while section (3) 116 has around 90degrees separation from sector (1) 112. As a result, the system isconfigured toward choosing a STA towards which sector (3) as the bestsector for a preferred next-hop secondary path. Greater angularseparation generally leads to improved node separation and thus improvedindependence.

4.5. Routing Protocol Description.

4.5.1. Protocol Operation.

FIG. 13 illustrates an example embodiment 130 of the disclosed routingprotocol in which the source STA seeks to secure primary and secondaryroutes. It should be noted that this flow diagram only depictsoperations from the standpoint of the source STA, not the activitiesoccurring at intermediate STAs and the destination STA. The baselinerouting protocol is an AODV which is tailored for directionaltransmissions according to the technology of this disclosure. Theprotocol is triggered 132 by the source STA, as it is an on-demandrouting protocol, whereupon receiving 134 a packet intended for adestination which is not found in the list of its neighbors. The sourceSTA can start the routing protocol by setting the route flag to primary(e.g., 0) and creating 136 and sending (transmitting) 138 the extendedRREQ to the neighbor STAs in a directional mode. The primary route rulesat the source STA, destination STA and the intermediate STAs (possiblerelays) follow those of the baseline routing protocol. A reply isreceived 140 and processed from a neighbor STA, in which the primarypath next hop is recorded 142.

After the primary route is secured, the source STA triggers the pathdiscovery of a secondary route. The secondary route is selected to bespatially uncorrelated with the primary route, this commences withselecting 144 links of neighbor STAs uncorrelated with the primary path.This step is depicted in greater detail in FIG. 15. The path flag is setto secondary (e.g., one) and an RREQ is prepared 146, and sent(transmitted) 148 to candidate relays from ranked neighbor nodes. Inresponse to this, a response (RREP) is received from a neighbor node 150and processed to set the secondary path. The source station transmits152 data along the primary path to the next-hop station, and alsotransmits 154 data along the secondary path to the next-hop STA, afterwhich this processing ends 156.

FIG. 14 illustrates an example embodiment 170 of processing an RREQ atintermediate nodes with primary and secondary path discovery. Theintermediate STAs and the destination follow different rules whenreceiving the secondary RREQ in order to discover an end-to-end routethat is not overlapped with the primary route, as seen in the figure.Process commences 172 with an RREQ being received 174 and processed 176at this intermediate node. A check is made 178 of SA, DA, broadcast IDand RREQ route flag to determine if these are the same as the previousRREQ. If they are the same, then the received RREQ is designated 180 assecondary, the RREQ is then dropped 182 to end 184 the process.Otherwise, if in block 178 these fields are not the same as the previousRREQ, then block 186 is executed to check if the RREQ flag is set toprimary. If it is not set to primary, then block 188 performs a check ifthe received previous RREP has same SA, DA, and BC ID. If previous RREPhad these same field values, then a jump to block 182 is made to dropthe RREQ, and end 184 the process. Otherwise, if either the route flagchecked in block 186 is primary, or the previous RREP checked in block188 did not have the same values, then block 190 is executed to updatethe path cost metric, and to forward the RREQ to neighbor STAs 192 thenend 184 the process.

4.5.2. Link Selection STAs Uncorrelated with Primary Path.

The source STA after securing the primary path prepares the secondaryRREQ to be transmitted to some selected neighbor STAs. As explainedpreviously, BF training information is retrieved to preclude selecting aSTA that has a best sector that is highly correlated with the bestsector to the primary path next-hop relay.

FIG. 15 illustrates this process 190 of selecting links of neighbor STAwhich are uncorrelated with the primary path. The process commences 192with best sector information retrieved 194 toward the next hop STA onthe primary path. Then best sector spatial angle θ is recorded 196toward next hop STA on the primary path. A spatial correlation thresholdα is set (or was previously set) 198, then a list of N neighbors isretrieved 200, with a local list (loop counter) being initialized 202. Aloop check 204 is made (alternatively check can be at bottom of loop) ifthe local loop has been performed for all of the N neighbors; if yes,then block 206 is executed to save the updated list of K STAs, and endthe process 208. Otherwise, the loop is executed and best sectorinformation is retrieved 210 toward the nth STA, and best sector spatialangle ϕ(n) towards the nth STA is recorded 212. A check is then made 214if the absolute value of spatial angle θ−ϕ (n) is less than spatialcorrelation threshold α. If the spatial angle is not less, then the STAis acceptable (will remain on the list) and a jump is made to block 218to increment the loop counter and jump back to block 204 at the top ofthe loop. Otherwise, with a non-sufficiently diverse angle, block 216 isexecuted which drops nth STA from the reliable peer STA list, beforereturning to the top of the list.

FIG. 16 is a geometric depiction 230 of this route selection process, inrelation to STAs A, B and C, based on the angles. It can be seen thatangle α can selected based on the minimum distance d_min between twoSTAs that assumes blockage on one would not affect the other STA. In thefigure, the value r_avg is an average distance between a transmittingSTA “A” and two candidate relays “B” and “C”. For example if d_min=0.5meters and r_avg=2 meters, then from basic geometry, using the inscribedangle conjecture and Thales' Theorem:

$\alpha = {2 \star {\sin^{- 1}\frac{d\_ min}{2 \star {r\_ avg}}}}$

In this example α is approximately 15 degrees.

This threshold α is utilized to compare the best sector horizontal angletowards the relay on the primary path, θ, with the best sectorhorizontal angle towards the nth candidate relay on a secondary path,ϕ(n). At the end of this procedure K STAs out of N reliable STAs areassumed to have spatially uncorrelated links with the link of theprimary path relay.

FIG. 17A through FIG. 17E illustrate applying the disclosed routingprotocol on an example mmWave mesh network, shown with STAs A-G. Inparticular, the figures depict and example of primary and secondary pathdiscovery on the network showing bidirectional links between STAs inFIG. 17A. The propagation of a primary RREQ (solid) is shown in FIG.17B. The primary route is selected as seen in FIG. 17C. Propagation ofthe RREQ for the secondary path (dashed) according the rules explainedin the current embodiments is seen in FIG. 17D, with the cross signreferring to dropping of the RREQ packet at the receiving STA. In FIG.17E a secondary route is seen selected.

Thus, in the above figures an example mesh network demonstrated STAsexchanging data using the disclosed routing protocol. First, an extendedRREQ with primary flag is propagated (from STA A in FIG. 17B) to enablediscovery of the primary path. After the reception of RREP at the sourceand securing the discovery of the primary path discovery (seen in FIG.17C), the secondary path RREQ is propagated (FIG. 17D). In the figure,the source STA (STA A) opted not to send the secondary RREQ to STA C asthe link to STA C has high spatial correlation with the link to STA D onthe primary path. In addition, intermediate STAs on the primary path areconfigured to drop any received RREQ for the secondary path, which isdepicted with the cross signs, for the secondary path RREQ arriving atSTA D. Upon securing the secondary path (FIG. 17E) through the use ofthe proposed routing protocol, the same data content is transmitted inthe two routes simultaneously.

The disclosed routing protocol is expected to increase the robustnessand reliability of routing data despite link blockage, antennamisalignments, channel fading effects, and similar instances whichreduce signal levels.

5. Data Reception from Two Routes at the Destination STA.

5.1. Uncoordinated Reception.

The simplest method for the destination STA to process the data contentsfrom the two routes is to receive the data without any form ofcoordination. The higher layers of the OSI model will detect anyduplication in the packets and duplicate packets can be dropped.

FIG. 18 depicts the data transmission by the last-hop relay on theprimary path and the last-hop relay on the secondary path and theacknowledgment sent by the destination. These transmissions areuncoordinated. The packets received at the destination from the last-hoprelay on the secondary path are designated duplicate and dropped,depicted by the cross sign in the figure. These packets have beencorrectly received by the destination STA from the primary path.

5.2. Coordinated Reception—Combining Received Signal Power.

The reception of the data contents from the two routes at thedestination STA can be coordinated. In at least one embodiment, thedisclosure achieves coordination by enabling the combination of thereceived signals from the last-hop relays at the physical layer. Thiscombination improves the overall received signal strength and thusdecreases the chances of reception errors.

FIG. 19 depicts the coordination of these data transmissions. A RTS issent by primary relay, to which a destination responds by a CTS frame toboth relays. The CTS frame specifies the transmission time given theknowledge of the propagation time between the destination and bothrelays and the time consumed in the handshaking process. Thishandshaking process allows reception of the two signals from both relaysalmost at the same exact time. The messaging needed for this type ofcoordination is depicted in the next figure.

FIG. 20 illustrates messaging flow 290 for performing the above form ofcoordination between primary relay, secondary relay, and destinationSTA, in performing a handshaking period 292 and data transmission period294. During handshaking 292, the primary relay transmits 296 a datarouting directional RTS frame. The destination STA transmits 298 a datarouting directional CTS frame to the primary relay. The destination STAtransmits 300 a data routing directional CTS frame to secondary relay.In the data transmission period 294, the primary relay transmits 302data to the destination STA. The secondary relay transmits 304 data tothe destination STA. The destination STA transmits an acknowledgement(ACK) 306 to the primary relay. The destination STA transmits anacknowledgement (ACK) 308 to the secondary relay.

FIG. 21A and FIG. 21B illustrate an example embodiment 310 of logic(programming) implemented at the destination STA showing simultaneousdata packet reception at the destination STA from the primary andsecondary relays. Execution starts 312 in FIG. 21A with an RTS received314 from a primary relay, and is processed 316. The destination STA thenapplies BF weights 318 toward the primary relay. A routing CTS is thentransmitted 320 to the primary relay. Then secondary relay informationis retrieved 322, to which transmit BF weights are applied 324, uponwhich the routing CTS is transmitted 326 to the secondary relay. Data isreceived and processed 328 from the primary and secondary relays. Thenin FIG. 21B, a check is made 330 if the data was received correctly. Ifit was received correctly, then transmit BF weights are applied 332toward the primary relay, and an ACK frame is sent 334 to the primaryrelay. Similarly, BF weights are applied 336 toward the secondary relay,and an ACK frame is sent 338 to the secondary relay, to end the process340. Returning to block 330, if the data was not received correctly,then the incorrectly received packets are dropped 342, and the processends 340.

5.2. Coordinated Reception—Conditional Reception from Secondary Route.

FIG. 22A and FIG. 22B illustrate example embodiments 350, 370 oftransmissions by the primary relay, destination STA, and secondary pathrelay. In FIG. 22A, data is shown being received correctly by theprimary path relay at the destination. In FIG. 22B data transmission bythe secondary path relay is shown being triggered since the datareception from the primary relay was deemed a failure by the destinationSTA.

The above example depicts another form of coordination of the receptionof the data contents from the two routes at the destination STA. If thedestination STA correctly receives the data packets from the relay ofthe primary path, then it acknowledges this reception to the relay onthe primary path. The relay on the secondary path drops the packetssince it did not receive a solicitation of communications. Thiscondition is seen in the FIG. 22A. On the other hand, if the data isreceived in error at the destination from the primary relay, then thedestination STA solicits the relay on the secondary path through a CTSframe to transmit the data packets as depicted in FIG. 22B.

FIG. 23 illustrates a messaging sequence 390 for data transmission bythe secondary path relay when the transmission by the primary path relayfails. At the top of the figure is seen the primary relay, secondaryrelay, and destination STA. The primary relay transmits 392 data to adestination STA, in response to which the destination STA transmits 394a routing CTS directional frame to a secondary relay. This secondaryrelay transmits 396 data to the destination STA, which then sends an ACKback 398 to the secondary relay.

FIG. 24A and FIG. 24B illustrate an example embodiment 410 ofconditional data packet reception at the destination STA from thesecondary STA. Processing commences 412 in FIG. 24A with RTS received414 from a primary relay, and its RTS packet contents processed 416.Transmit BF weights are applied 418 toward the primary relay, andtransmitted 420 to the primary relay. Data is then processed 422 fromthe primary relay. A check is made 424 to determine if the data wasreceived correctly. If correctly received, then transmit BF weights areapplied 426 toward the primary relay, and an ACK frame sent 428 to theprimary relay before the process ends 432 as seen in FIG. 24B.Otherwise, if the data was not correctly received at block 424, thensecondary relay information is retrieved 432 in FIG. 24B, transmit BFweights applied 434 toward secondary relay, and a routing CTS frame sent436 to the secondary relay. Data is received and processed 438 from thesecondary relay, and a check is made 440 if the data was receivedcorrectly. If it was correctly received, then processing ends 430.Otherwise, the incorrectly received packets are dropped 442 beforeending processing 430.

FIG. 25 illustrates an example embodiment 490 of asingle-input-single-output (SISO) station (STA) configured for operationaccording to the technology of this disclosure. A data line 492 is seenconnecting from a source/sink device through connection 494 to a bus 496to a memory 498, controller 502, TX data processor 500, and RX dataprocessor 504. A modulator/demodulator (mod/demod) 506 is shown havingmodulator 508 and demodulator 510, and being coupled to the spatialprocessor 512 having antennas 514. TX data processor 500 is coupled foroutput through a modulator 508, while RX data processor 504 is coupledfor input from a demodulator 510.

It will be noted that the controller accesses the memory and providescontrol signals to the TX data processor to access the bits from thedata sink and perform scrambling, coding, interleaving of raw data, andmapping to data symbols or to the RX processor to de-map the receiveddata symbols and perform deinterleaving, decoding, and descramblingoperations. The modulator processes and modulates the digital symbols toanalog symbols. The demodulator receives the analog symbols anddemodulates to digital symbols.

When the station operates beamforming to a transmitting signal, the beampattern to be utilized is commanded from TX data processor 500 to themodulator/demodulator 506. The modulator/demodulator interprets thegiven command and generates a command that is fed to analogue spatialprocessor 512. As a result, analogue spatial processor 512 shifts phasesin each of its transmitting antenna elements to form the commanded beampattern. When the station operates beamforming to a receiving signal,the beam pattern to be used is commanded from controller 504 and RX dataprocessor 504 to the modulator/demodulator 506. Modulator/demodulator506 interprets the given command and generates a command that is fed toanalogue spatial processor 512. As a result, analogue spatial processor512 shifts phases in each of its receiving antenna elements to form thecommanded beam pattern. When the station receives a signal, the receivedsignal is fed to controller 502, via analogue spatial processor 512,modulator/demodulator 506, and RX data processor 504. The controller 502determines the content of the received signal, and triggers appropriatereactions, and stores information in memory 498 as described above. Allthe management frames, exchanged packets described above are determinedand generated by controller 502. When a packet is to be transmitted onthe air, the packet generated by the controller 502 is fed to analoguespatial processor 512 via TX data processor 500 andmodulator/demodulator 506, whereas the transmitting beam pattern iscontrolled as described above simultaneously.

FIG. 26 illustrates an example embodiment 530 of amultiple-input-multiple-output (MIMO) station (STA) configured foroperation according to the technology of this disclosure. It will benoted that the controller, modulators and demodulators perform the samebasic functions as described for the previous embodiment. The TX spatialprocessor performs spatial precoding and spatial mapping of the spatialstreams to match the transmit chains. The RX spatial processor performsspatial de-mapping of spatial streams received from the differentreceive chains and performs spatial decoding.

A data line 532 is seen connecting from a source/sink device throughconnection 534 to a bus 536 to a memory 538, controller 542, TX dataprocessor 540, and RX data processor 544. In view of there beingmultiple inputs and outputs, TX data processor 540 couples to both thecontroller 542 and to a TX spatial processor 546. Similarly, RX dataprocessor 544 couples to the controller 542, and receives data from a RXspatial processor 548. Multiple modulator/demodulator (mod/demod)devices 550 a-550 n (for example two or more) are coupled to an analoguespatial processor 556, which has a plurality of antennas 558. Theindividual modulators 552 a-552 n, of mod/demod devices 550 a-550 n,receive TX inputs from TX spatial processor 546. In a similar manner theindividual demodulators 554 a-554 n, of mod/demod devices 550 a-550 n,receive RX inputs from antenna 558 of analog spatial processor 556 whichafter demodulation are passed to RX spatial processor 548.

When the station operates beamforming to a transmitting signal, the beampattern and MIMO configuration to be used are commanded from TX dataprocessor 540 to the TX spatial processor 546 and modulator/demodulator550 a-550 n. The modulator/demodulator 550 a-550 n interprets the givencommand and generates commands that are fed to analogue spatialprocessor 556. As a result, analogue spatial processor 556 shifts phasesin each of its transmitting antenna elements 558 to form the commandedbeam pattern and MIMO configuration. When the station operatesbeamforming to a receiving signal, the beam pattern for use is commandedfrom controller 542 and RX spatial processor 548 to themodulator/demodulator 550 a-550 n. The modulator/demodulator 550 a-550 ninterprets the given command and generates commands that are fed toanalogue spatial processor 556. As a result, analogue spatial processor556 shifts phases in each of its receiving antenna elements to form thecommanded beam pattern with MIMO configuration. When the stationreceives a signal, the received signal is fed to Controller 542, viaanalogue spatial processor 556, modulator/demodulator 550 a-550 n, andRX spatial processor 548. The controller 542 determines the content ofthe received signal, and triggers appropriate reactions, and storesinformation in memory 538 as described above. All the management frames,exchanged packets described above are determined and generated bycontroller 542. When a packet is to be transmitted on the air, thepacket generated by the controller 542 is fed to analogue spatialprocessor 412 via TX data processor 540, TX spatial processor 546, andmodulator/demodulator 550 a-550 n, whereas the transmitting beam patternare controlled as described above simultaneously.

The enhancements described in the presented technology can be readilyimplemented within various wireless communication devices. It shouldalso be appreciated that wireless data communication devices aretypically implemented to include one or more computer processor devices(e.g., CPU, microprocessor, microcontroller, computer enabled ASIC,etc.) and one or more associated memories storing instructions (e.g.,RAM, DRAM, NVRAM, FLASH, computer readable media, etc.) wherebyprogramming (instructions) stored in the memory are executed on theprocessor to perform the steps of the various process methods describedherein.

It will also be appreciated that the computer readable media (memorystoring instructions) in these computation systems is “non-transitory”,which comprises any and all forms of computer-readable media, with thesole exception being a transitory, propagating signal. Accordingly, thedisclosed technology may comprise any form of computer-readable media,including those which are random access (e.g., RAM), require periodicrefreshing (e.g., DRAM), those that degrade over time (e.g., EEPROMS,disk media), or that store data for only short periods of time and/oronly in the presence of power, with the only limitation being that theterm “computer readable media” is not applicable to an electronic signalwhich is transitory.

Embodiments of the present technology may be described herein withreference to flowchart illustrations of methods and systems according toembodiments of the technology, and/or procedures, algorithms, steps,operations, formulae, or other computational depictions, which may alsobe implemented as computer program products. In this regard, each blockor step of a flowchart, and combinations of blocks (and/or steps) in aflowchart, as well as any procedure, algorithm, step, operation,formula, or computational depiction can be implemented by various means,such as hardware, firmware, and/or software including one or morecomputer program instructions embodied in computer-readable programcode. As will be appreciated, any such computer program instructions maybe executed by one or more computer processors, including withoutlimitation a general purpose computer or special purpose computer, orother programmable processing apparatus to produce a machine, such thatthe computer program instructions which execute on the computerprocessor(s) or other programmable processing apparatus create means forimplementing the function(s) specified.

Accordingly, blocks of the flowcharts, and procedures, algorithms,steps, operations, formulae, or computational depictions describedherein support combinations of means for performing the specifiedfunction(s), combinations of steps for performing the specifiedfunction(s), and computer program instructions, such as embodied incomputer-readable program code logic means, for performing the specifiedfunction(s). It will also be understood that each block of the flowchartillustrations, as well as any procedures, algorithms, steps, operations,formulae, or computational depictions and combinations thereof describedherein, can be implemented by special purpose hardware-based computersystems which perform the specified function(s) or step(s), orcombinations of special purpose hardware and computer-readable programcode.

Furthermore, these computer program instructions, such as embodied incomputer-readable program code, may also be stored in one or morecomputer-readable memory or memory devices that can direct a computerprocessor or other programmable processing apparatus to function in aparticular manner, such that the instructions stored in thecomputer-readable memory or memory devices produce an article ofmanufacture including instruction means which implement the functionspecified in the block(s) of the flowchart(s). The computer programinstructions may also be executed by a computer processor or otherprogrammable processing apparatus to cause a series of operational stepsto be performed on the computer processor or other programmableprocessing apparatus to produce a computer-implemented process such thatthe instructions which execute on the computer processor or otherprogrammable processing apparatus provide steps for implementing thefunctions specified in the block(s) of the flowchart(s), procedure (s)algorithm(s), step(s), operation(s), formula(e), or computationaldepiction(s).

It will further be appreciated that the terms “programming” or “programexecutable” as used herein refer to one or more instructions that can beexecuted by one or more computer processors to perform one or morefunctions as described herein. The instructions can be embodied insoftware, in firmware, or in a combination of software and firmware. Theinstructions can be stored local to the device in non-transitory media,or can be stored remotely such as on a server, or all or a portion ofthe instructions can be stored locally and remotely. Instructions storedremotely can be downloaded (pushed) to the device by user initiation, orautomatically based on one or more factors.

It will further be appreciated that as used herein, that the termsprocessor, computer processor, central processing unit (CPU), andcomputer are used synonymously to denote a device capable of executingthe instructions and communicating with input/output interfaces and/orperipheral devices, and that the terms processor, computer processor,CPU, and computer are intended to encompass single or multiple devices,single core and multicore devices, and variations thereof.

From the description herein, it will be appreciated that that thepresent disclosure encompasses multiple embodiments which include, butare not limited to, the following:

1. A wireless communication apparatus, comprising: (a) a wirelesscommunication circuit configured for wirelessly communicating with otherwireless communication stations; (b) a computer processor coupled tosaid wireless communication circuit; (c) a non-transitorycomputer-readable memory storing instructions executable by the computerprocessor; and (d) wherein said instructions, when executed by thecomputer processor, perform steps comprising: (d)(i) communicating withthe other wireless communication stations utilizing a routing protocol;(d)(ii) performing primary and secondary path discovery in establishingcommunications with a destination wireless communication station,through intermediate wireless communication stations; (d)(iii)determined by the processor that intermediate station of the primary andsecondary path to be selected such that the antenna pattern for theprimary and secondary path are spatially uncorrelated, using BF traininginformation toward candidate intermediate stations; and (d)(iv)transmitting data on the primary and the same data on the secondarypath, for receipt by the destination wireless communication stationtoward overcoming link blockages of the primary path in response to datareceived on the secondary path.

2. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer are configured to provide reception at adestination station which is selected from the group of reception typesconsisting of: uncoordinated reception, coordinated reception bycombining received signal powers, or coordinated reception withconditional reception from the secondary routing path.

3. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer are configured for utilizing ready-to-send(RTS), clear-to-send (CTS) procedures.

4. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer are configured for utilizing a modifiedRTS frame and CTS frame to coordinate transmissions on both the primaryand secondary paths.

5. The apparatus of any preceding embodiment, intermediate stationsdetermine if the secondary path segments are not part of the primarypath and perform adjusting a path cost metric to assure said secondarypath is independent of said primary path.

6. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer are configured for utilizing a handshakingmechanism at the destination wireless communication station tocoordinate the reception of data from the two routes to minimize errorsand delay in reception.

7. The apparatus of any preceding embodiment, wherein said routingprotocol is an extension of an ad-hoc on-demand distance vector (AODV)routing protocol.

8. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for performingprimary and secondary path discovery in establishing communications witha destination wireless communication station in response to utilizingextended routing request (RREQ) and routing reply (RREP) informationelements sent to neighboring stations.

9. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for utilizingsaid extended routing request (RREQ) and routing reply (RREP)information elements which contain a distinct extended identifier whichdifferentiates them from a conventional (non-extended) routing request(RREQ) and routing reply (RREP), and each contain a routing flagindicating a selection between a primary routing path and a secondaryrouting path.

10. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for adjustingpath cost metric on an intermediate station (STA) in response to signalprocessing capability of a station on that path.

11. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for identifyingindependence of the secondary path segment it belongs, so that anintermediate station (STA) can identify this independence with respectto the primary path.

12. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for adjusting thepath cost metric in an intermediate station (STA) in response toindependence of the secondary path segment it belongs to with respect tothe primary path.

13. The apparatus of any preceding embodiment, wherein said wirelesscommunication circuit comprises a single-input-single-output (SISO)wireless communication circuit.

14. The apparatus of any preceding embodiment, wherein saidsingle-input-single-output (SISO) wireless communication circuit,comprises: (a) a transmitter data processor which receives source data,processes it for transmission according to the routing protocol; (b) amodulator receiving digital output from said transmitter data processor,converting it to an analog TX signal; (c) an analog spatial processorcoupled to multiple antennas, and configured for receiving said analogTX signal and coupling this to the multiple antennas for wirelesstransmission; (d) a demodulator receiving analog input from said analogspatial processor, converting it to a digital signal; and (e) a receiverdata processor which receives digital signals from said demodulator, andgenerates a sink data stream for output.

15. The apparatus of any preceding embodiment, wherein said wirelesscommunication circuit comprises a multiple-input-multiple-output (MIMO)wireless communication circuit.

16. The apparatus of any preceding embodiment, wherein saidmultiple-input-multiple-output (MIMO) wireless communication circuit,comprises: (a) a transmitter data processor which receives source data,processes it for transmission according to the routing protocol; (b) atransmitter spatial processor which spatially converts the output fromsaid transmitter data processor to spatial outputs; (c) a plurality ofmodulators each receiving one of the spatial outputs and converting itto an analog TX signal; (d) an analog spatial processor coupled tomultiple antennas, and configured for receiving said analog TX signalfrom each of said plurality of modulators and coupling this to themultiple antennas for wireless transmission; (e) a plurality ofdemodulators receiving analog input from said analog spatial processor,converting it to digital receiver signals; (f) a receiver spatialprocessor which receives digital receiver signals from said plurality ofdemodulators, and spatially processes them into a digital data output;and (g) a receiver data processor which receives digital data outputfrom said receiver spatial processor from which it generates a sink datastream for output.

17. The apparatus of any preceding embodiment, wherein said apparatus isutilized in a communication application selected from the group ofwireless communication applications consisting of: wireless local areanetworks (WLANs), wireless personal area networks (WPANs), wirelessmultiple hop relaying networks, peer-to-peer (P2P) communications,outdoor wireless communications, Wi-Fi networks, Internet of things(IoT) applications, backhauling of data by mesh networking, nextgeneration cellular networks with D2D communications, 802.11 networks,and ZigBee.

18. A wireless communication apparatus, comprising: (a) a wirelesscommunication circuit configured for wirelessly communicating with otherwireless communication stations; (b) a computer processor coupled tosaid wireless communication circuit; and (c) a non-transitorycomputer-readable memory storing instructions executable by the computerprocessor; (d) wherein said instructions, when executed by the computerprocessor, perform steps comprising: (d)(i) communicating with the otherwireless communication stations utilizing a routing protocol; (d)(ii)performing primary and secondary path discovery in establishingcommunications with a destination wireless communication station,through intermediate wireless communication stations; (d)(iii)determined by the processor that intermediate station of the primary andsecondary path to be selected such that the antenna pattern for theprimary and secondary path are spatially uncorrelated, using BF traininginformation toward candidate intermediate stations; (d)(iv) utilizingready-to-send (RTS), clear-to-send (CTS) procedures, with a modified RTSframe and CTS frame, to coordinate transmissions on both the primary andsecondary paths; and (d)(v) transmitting data on the primary and thesame data on the secondary path, for receipt by the destination wirelesscommunication station toward overcoming link blockages of the primarypath in response to data received on the secondary path.

19. The apparatus of any preceding embodiment, wherein said instructionswhen executed by the computer processor are configured for intermediatestations determining if the secondary path segments are not part of theprimary path and adjusting a path cost metric to assure said secondarypath is independent of said primary path.

20. A method for wireless communication between stations, comprising:(a) communicating with other wireless communication stations utilizing arouting protocol which controls a wireless communication circuit havinga transmitter and receiver; (b) performing primary and secondary pathdiscovery in establishing communications with a destination wirelesscommunication station, through intermediate wireless communicationstations; (c) determining by intermediate stations that secondary pathsegments are not part of the primary path and adjusting a path costmetric to assure said secondary path is independent of said primarypath; and (d) transmitting the same data on both the primary and thesecondary path.

Although the description herein contains many details, these should notbe construed as limiting the scope of the disclosure but as merelyproviding illustrations of some of the presently preferred embodiments.Therefore, it will be appreciated that the scope of the disclosure fullyencompasses other embodiments which may become obvious to those skilledin the art.

In the claims, reference to an element in the singular is not intendedto mean “one and only one” unless explicitly so stated, but rather “oneor more.” All structural and functional equivalents to the elements ofthe disclosed embodiments that are known to those of ordinary skill inthe art are expressly incorporated herein by reference and are intendedto be encompassed by the present claims. Furthermore, no element,component, or method step in the present disclosure is intended to bededicated to the public regardless of whether the element, component, ormethod step is explicitly recited in the claims. No claim element hereinis to be construed as a “means plus function” element unless the elementis expressly recited using the phrase “means for”. No claim elementherein is to be construed as a “step plus function” element unless theelement is expressly recited using the phrase “step for”.

What is claimed is:
 1. A wireless communication apparatus, comprising:(a) a wireless communication circuit configured for wirelesslycommunicating with other wireless communication stations; (b) a computerprocessor coupled to said wireless communication circuit; (c) anon-transitory computer-readable memory storing instructions executableby the computer processor; and (d) wherein said instructions, whenexecuted by the computer processor, perform steps comprising: (i)communicating with the other wireless communication stations utilizing arouting protocol; (ii) performing primary and secondary path discoveryin establishing communications with a destination wireless communicationstation, through intermediate wireless communication stations; (iii)utilizing BF training information in selecting intermediate stationsalong the primary and secondary path to assure that the antenna patternfor the primary and secondary path are spatially uncorrelated; (iv)wherein said BF training information is collected in response to abeamforming (BF) training process of training an initiator of thetraining process with an initiator sector sweep (ISS), training a peerstation responding to the ISS with a responder sector sweep (RSS), andreturning sector sweep (SSW) feedback comprising BF traininginformation; and (v) transmitting data on the primary and the same dataon the secondary path, for receipt by the destination wirelesscommunication station toward overcoming link blockages of the primarypath in response to data received on the secondary path.
 2. Theapparatus of claim 1, wherein said instructions when executed by thecomputer are configured to provide reception at a destination stationwhich is selected from the group of reception types consisting of:uncoordinated reception, coordinated reception by combining receivedsignal powers, or coordinated reception with conditional reception fromthe secondary routing path.
 3. The apparatus of claim 1, wherein saidinstructions when executed by the computer are configured for utilizingready-to-send (RTS), clear-to-send (CTS) procedures.
 4. The apparatus ofclaim 3, wherein said instructions when executed by the computer areconfigured for utilizing a modified RTS frame and CTS frame tocoordinate transmissions on both the primary and secondary paths.
 5. Theapparatus of claim 1, wherein said instructions when executed by thecomputer are configured for having intermediate stations determine ifthe secondary path segments are not part of the primary path and performadjusting a path cost metric to assure said secondary path isindependent of said primary path.
 6. The apparatus of claim 1, whereinsaid instructions when executed by the computer are configured forutilizing a handshaking mechanism at the destination wirelesscommunication station to coordinate the reception of data from the tworoutes to minimize errors and delay in reception.
 7. The apparatus ofclaim 1, wherein said routing protocol is an extension of an ad-hocon-demand distance vector (AODV) routing protocol.
 8. The apparatus ofclaim 1, wherein said instructions when executed by the computerprocessor are configured for performing primary and secondary pathdiscovery in establishing communications with a destination wirelesscommunication station in response to utilizing extended routing request(RREQ) and routing reply (RREP) information elements sent to neighboringstations.
 9. The apparatus of claim 8, wherein said instructions whenexecuted by the computer processor are configured for utilizing saidextended routing request (RREQ) and routing reply (RREP) informationelements which contain a distinct extended identifier whichdifferentiates them from a conventional (non-extended) routing request(RREQ) and routing reply (RREP), and each contain a routing flagindicating a selection between a primary routing path and a secondaryrouting path.
 10. The apparatus of claim 1, wherein said instructionswhen executed by the computer processor are configured for adjustingpath cost metric on an intermediate station (STA) in response to signalprocessing capability of a station on that path.
 11. The apparatus ofclaim 1, wherein said instructions when executed by the computerprocessor are configured for identifying independence of the secondarypath segment it belongs, so that an intermediate station (STA) canidentify this independence with respect to the primary path.
 12. Theapparatus of claim 1, wherein said instructions when executed by thecomputer processor are configured for adjusting the path cost metric inan intermediate station (STA) in response to independence of thesecondary path segment it belongs to with respect to the primary path.13. The apparatus of claim 1, wherein said wireless communicationcircuit comprises a single-input-single-output (SISO) wirelesscommunication circuit.
 14. The apparatus of claim 13, wherein saidsingle-input-single-output (SISO) wireless communication circuit,comprises: (a) a transmitter data processor which receives source data,processes it for transmission according to the routing protocol; (b) amodulator receiving digital output from said transmitter data processor,converting it to an analog TX signal; (c) an analog spatial processorcoupled to multiple antennas, and configured for receiving said analogTX signal and coupling this to the multiple antennas for wirelesstransmission; (d) a demodulator receiving analog input from said analogspatial processor, converting it to a digital signal; and (e) a receiverdata processor which receives digital signals from said demodulator, andgenerates a sink data stream for output.
 15. The apparatus of claim 1,wherein said wireless communication circuit comprises amultiple-input-multiple-output (MIMO) wireless communication circuit.16. The apparatus of claim 15, wherein saidmultiple-input-multiple-output (MIMO) wireless communication circuit,comprises: (a) a transmitter data processor which receives source data,processes it for transmission according to the routing protocol; (b) atransmitter spatial processor which spatially converts the output fromsaid transmitter data processor to spatial outputs; (c) a plurality ofmodulators each receiving one of the spatial outputs and converting itto an analog TX signal; (d) an analog spatial processor coupled tomultiple antennas, and configured for receiving said analog TX signalfrom each of said plurality of modulators and coupling this to themultiple antennas for wireless transmission; (e) a plurality ofdemodulators receiving analog input from said analog spatial processor,converting it to digital receiver signals; (f) a receiver spatialprocessor which receives digital receiver signals from said plurality ofdemodulators, and spatially processes them into a digital data output;and (g) a receiver data processor which receives digital data outputfrom said receiver spatial processor from which it generates a sink datastream for output.
 17. The apparatus of claim 1, wherein said apparatusis utilized in a communication application selected from the group ofwireless communication applications consisting of: wireless local areanetworks (WLANs), wireless personal area networks (WPANs), wirelessmultiple hop relaying networks, peer-to-peer (P2P) communications,outdoor wireless communications, Wi-Fi networks, Internet of things(loT) applications, backhauling of data by mesh networking, nextgeneration cellular networks with D2D communications, 802.11 networks,and ZigBee.
 18. A wireless communication apparatus, comprising: (a) awireless communication circuit configured for wirelessly communicatingwith other wireless communication stations; (b) a computer processorcoupled to said wireless communication circuit; (c) a non-transitorycomputer-readable memory storing instructions executable by the computerprocessor; and (d) wherein said instructions, when executed by thecomputer processor, perform steps comprising: (i) communicating with theother wireless communication stations utilizing a routing protocol; (ii)performing primary and secondary path discovery in establishingcommunications with a destination wireless communication station,through intermediate wireless communication stations; (iii) utilizing BFtraining information in selecting intermediate stations along theprimary and secondary path to assure that the antenna pattern for theprimary and secondary path are spatially uncorrelated; (iv) wherein saidBF training information is collected in response to a beamforming (BF)training process of training an initiator of the training process withan initiator sector sweep (ISS), training a peer station responding tothe ISS with a responder sector sweep (RSS), and returning sector sweep(SSW) feedback comprising BF training information; (v) utilizingready-to-send (RTS), clear-to-send (CTS) procedures, with a modified RTSframe and CTS frame, to coordinate transmissions on both the primary andsecondary paths; and (vi) transmitting data on the primary and the samedata on the secondary path, for receipt by the destination wirelesscommunication station toward overcoming link blockages of the primarypath in response to data received on the secondary path.
 19. Theapparatus of claim 18, wherein said instructions when executed by thecomputer processor are configured for intermediate stations determiningif the secondary path segments are not part of the primary path andadjusting a path cost metric to assure said secondary path isindependent of said primary path.